Catalytic cracking is a petroleum refining process which is applied commercially on a very large scale. A majority of the refinery gasoline blending pool in the United States is produced by this process. In the catalytic cracking process heavy hydrocarbon fractions are converted into lighter products by reactions taking plate at elevated temperature in the presence of a catalyst, with the majority of the conversion or cracking occurring in the vapor phase. The feedstock is thereby converted into gasoline, distillate and other liquid cracking products as well as lighter gaseous cracking product.
During catalytic cracking, heavy material, known as coke, is deposited onto the catalyst. This reduces its catalytic activity and regeneration is desired. After removal of hydrocarbons from the spent cracking catalyst, regeneration is accomplished by burning off the coke which restores the catalyst activity. The three characteristics steps of the catalytic cracking can be therefore be distinguished: a cracking step in which the hydrocarbons are converted into lighter products, a stripping step to remove hydrocarbons adsorbed on the catalyst and a regeneration step to burn off coke from the catalyst. The regenerated catalyst is then reused in the cracking step.
The FCC process relies upon cyclones to physically separate vapor gases from solid catalyst particles. These mechanical devices are prone to failure and operating problems. When this occurs, catalyst losses increase. This can increase equipment erosion and unit emissions. The use of acoustic emission detectors allows on-line measurement of cyclone performance and assist in unit troubleshooting and monitoring.
Other objects and advantages of the present invention will become apparent to those skilled in the art upon a review of the following detailed description of the preferred embodiments and the accompanying drawings.